This invention relates to a system for recording and reproducting pulse code modulation signals (herein abbreviated PCM).
There have been previously known PCM recording and reproducing systems to which digital techniques are applied. One type of these systems utilizes a rotary head mechanism as in video tape recorders (which is abbreviated to VTR) while another type thereof utilizes a stationary multi-track head assembly as in audio tape recorders.
The utilization of a rotary head mechanism results in the relative speed between the head and a tape being as high as several tens of meters per second and therefore necessarily requires employment of mechanisms high in accuracy and complicated in construction. Accordingly the utilization of a rotary head mechanism has been disadvantageous in that it is restricted in utility and cost.
On the other hand, it is possible to simply and inexpensively realize mechanisms utilizing stationary multi-track head assemblies because the PCM signal is distributed among a multiplicity of tracks to thereby to decrease the recording density for each track. However the utilization of a stationary multi-track head assembly has been disadvantageous in that the resulting recording pattern is subjected to limitations as to the number of tracks, the number of frame synchronizing bits, the capacity of the associated buffer memory etc. Damages to the recording medium and dust adhering thereto inevitably cause the loss of some of recorded signals during reproduction. In addition, the conventional types have been able to sense and/or correct at most the loss of signal portions less than that portion of the record pattern corresponding to one sample and therefore they have been poor loss of long signal portions.
Accordingly it is an object of the present invention to provide a new and improved PCM recording and reproducing system with a stationary multi-track head assembly less in dependency of the number of tracks, the number of frame synchronizing bits, and the number of bits forming each portion of a PCM signal upon one another and effective for reducing the influence of dropouts.